Endocrinology, Vol 100, 380-386, Copyright © 1977 by Endocrine Society
Relation of gonadotropin secretion by pituitary grafts to spermatogenesis in hypophysectomized rats
KH Lu, HH Grandison, S Marshall and J Meites
In hypophysectomized male rats, 2 anterior pituitary (AP) grafts placed
underneath the kidney capsule partially prevented atrophy of the testes and
ventral prostate during a 17 day post-implantation period. Spermatogenesis
was partially maintained as revealed by histological examination of the
testes. The AP grafts released small amounts of LH and FSH and substantial
amounts of prolactin as determined by radioimmunoassay. Serum LH and FSH
were undetectable in the hypophysectomized rats with no AP grafts.
Inhibition of prolactin release by daily injections of ergocornine
methanesulfonate (ERG) did not significantly alter serum levels of FSH and
LH, spermatogenesis or testes and ventral prostate weights, indicating that
circulating levels of prolactin were not responsible for the partial
maintenance of spermatogenesis and prostate weight in these rats. Daily
injections of ovine prolactin also had no effect on spermatogenesis or
prolactin also had no effect on spermatogenesis or prostate weight in the
hypophysectomized rats, and there was no change in the histological
appearance of the testes and prostate. These observations indicate that
secretion of gonadotropins and not prolactin by AP grafts accounts for the
partial maintenance of spermatogenesis and prostate weight in
hypophysectomized, AP-grafted male rats during the experimental period
studied.
